This 4000 word essay was selected for a special issue of 'Image & Narrative' (Issue 18, September 2007), on 'Thinking Pictures', guest edited by Hanneke Grootenboer, author of 'The Rhetoric of Perspective' (University of Chicago Press, 2005). 'Image & Narrative' is a peer-reviewed e-journal on visual narratology, with essays reviewed by at least two members of the editorial board.

The essay addresses contemporary arguments on spectatorship within the philosophy of art. It examines different ways by which internal and external spectators negotiate painting's two perspectives: the absent scene represented by the picture's marked surface and the external point of view of a beholder, standing in real space.

The essay argues that if the imaginative engagement provided by an internal spectator (see Wollheim) renders the picture plane transparent, so that we might enter the virtual space of the painting, then in paintings integrated into their architectural contexts the surface plays a semantic role in both connecting and separating different realms. If the picture surface disappears for the internal spectator, then for works integrated into their architectural settings its status is heightened and negated as a threshold separating spatiotemporal realms.

The essay challenges semiotic accounts of painting. While linguistic derived semiotic accounts negate a spatial engagement, in Hubert Damisch's proposal that painting is a form of thinking, structure emerges from within the loop of the perspective paradigm. The essay argues, however, that if certain paintings 'think', they do so only in the sense that thought permeates a phenomenological whole where perception and imagination merge.

The essay is a development of 'A spatiality of situation', published by Art In-sight, Filmwaves magazine (no. 31, 2006), guest edited with Adam Kossoff. A related paper, 'Levels of Reality', was given at the 'Real Things: matter, materiality, representation' conference at the University of York, 5-8 July 2007.